. >>> just because you signed up for obama care does not mean you are covered. it's 90% functional. at peak times, signing up could not work. >> reporter: the front end of healthcare.gov was working well. 375,000 users say the administrators between midnight and noon. senior administration officials told nbc news as of 5:30 today, 750,000 users on healthcare.gov. websites have a front end and back end. the back could be a problem. the front end is what you log on to amazon.com and click you want to buy a lightbulb. that's the front end. then the system has to kick out an order to send you a lightbulb. healthcare.gov has problems with both ends. at a can have fee shop in d.c., robert tried to get on healthcare.gov. it didn't crash or freeze, but this note, the site cannot handle a surge of users. the white house says 375,000 logged on between midnight and noon. >> we want to make sure their experience is vastly improved. >> reporter: it was this weekend in northern virginia. obama care navigators got people logged in and signed up. >> this was my third time on the website, you know,